JPH06155140A - Method and device for cutting cold pilger rolled pipe into shortened length - Google Patents

Abstract

PURPOSE: To cut a cold pilgered tube without causing any problem and without afterward cutting a tube edge part during rolling on a cold pilger rolling mill with reciprocating rolling stand performing intermittent advance and rotation of the tube in an area of the dead center of the rolling stand. CONSTITUTION: In a distance range determined by the material and dimensions behind a rolling zone, the rotation at a constant speed corresponding to the average rotational speed of the tube which twists a tube 4 temporarily and elastically is forcibly applied to the tube which is cut within the distance range. The apparatus for carrying out this method is provided with a cutting apparatus installed at a distance (a) permitting elastic torsion of the tube 4. The cutting apparatus has a clamping bush 10 which surrounds and clamps the peripheral edge of the tube and is rotatingly-driven constantly.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a cold pilger mill having a reciprocating roll stand, in which the pipe is intermittently advanced and intermittently rotated in the region of one or two dead centers of the roll stand. And apparatus for cutting cold pilger rolled tubes to shorten them during rolling.

[0002]

2. Description of the Related Art Unlike other tube rolling systems, there are problems peculiar to cutting a pipe to be rolled by a cold pilger mill to shorten it. This is because in the typical Pilger system, the pipe to be rolled is periodically rolled at different speeds, and additionally, it is shockedly rotated.

In order to avoid long outlet lengths and thus high costs during machine assembly and factory installation,
When cutting a pipe to be rolled by Pilger rolling behind a cold Pilger mill during operation of a rolling mill, known prior art (German Patent Publication No. 3105780) discloses:
A roll knife type cutting device is used.

In this device, however, the roll knife causes burrs on the inside of the tube end, which hinders the introduction of the mandrel during the subsequent drawing and rolling of the tube. This problem,
After the pipe is cut during rolling, it is shortened again only by a short end section, usually with a rotary cutter (Trennscheiben) or saw (Saegen). Even in that case, a slight burr is generated, but this can be removed by a brush without any problem.

It is theoretically possible to use a rotary cutter or saw as well to cut the tube during rolling, but the intermittent rotation of the tube causes a non-uniform and excess material on the cutting tool. Supplied, which causes the cutting tool to be overloaded and damaged or destroyed.

[0006]

The object of the present invention is, starting from the above-mentioned drawbacks and problems of the prior art, a problem-free cutting and shortening of the tube during rolling by a cold pilger mill. It is an object of the invention to provide a cutting method and a device for carrying out this cutting method, which makes it possible to carry out without subsequent cutting of parts.

[0007]

SUMMARY OF THE INVENTION According to the invention, the above-mentioned object is to determine the average rotational speed of the tube, which is to elastically twist the tube temporarily within the spacing zone defined behind the rolling zone depending on the material and the dimensions. Corresponding constant speed rotation is forced on the tube and the cutting of the tube is accomplished by making this region.

[0008] The gist of the present invention is to clamp the pipe during cutting and to temporarily rotate it continuously at an average rotational speed without any shocking movement, whereby a constant amount of material is cut during cutting. . This allows the cutting method to be carried out during rolling of the pipe without breaking or damaging the tool.

In a further embodiment of the invention, the cutting of the tube is synchronized with the longitudinal advance movement of the tube, if the tube is also advanced in the longitudinal direction simultaneously with the rotation of the tube and during the cutting. Is done. Corresponding to the longitudinal feed rate, the cutting tool moves together with the tube in the same direction.

In the apparatus for carrying out the method for cutting a cold pilger rolled tube according to the invention to shorten it, the cold pilger mill roll stand exit is spaced from it to allow elastic twisting of the tube. A cutting device is provided in a position so as to be able to run along the tube axis, and the cutting device comprises a constant and rotationally driven clamping bush that surrounds and clamps the peripheral edge of the tube and a cutting and cutting tool.

By means of this device, the tube which rotates intermittently during the rolling process is caught by a clamping bush which is driven at a constant rotational speed at a corresponding distance from the roll stand. The intermittent rotation of the tube is equalized to a constant rotation.

The tube is then twisted in the elastic region, that is to say not to exceed the yield point of the tube material. This twist is harmless at low twist angles provided that the distance from the deformation zone of the roll stand is adequately maintained corresponding to the strength and yield point of the material to be cut.
During the continuous rotation of the tube, the tube is cut by the cutting tool, at which a uniform cutting speed can be reached.

In one embodiment of the invention, the cutting device is provided on a carriage which is movable on a path of travel, which is synchronous with the longitudinal pipe advance movement and can be driven linearly. Therefore, this trolley travels in the longitudinal direction along with the forward feed of the pipe,
Then, it is linearly driven via a clamping bush that clamps the peripheral edge of the pipe. The dolly clings firmly to the tube and is synchronized with each forward movement.

A linear drive in the form of a piston-cylinder unit is provided for returning the carriage.

The invention is advantageous because it makes it possible to utilize a cutting method for the cutting of pipes which forms only a few burrs which can be easily removed.

[0016]

The present invention will now be described in detail with reference to the drawings based on an embodiment.

FIG. 1 shows the device according to the invention in a considerably simplified manner. The cold Pilger mill is designated by 1. The cold pilger mill is reciprocated by the associated drive 2 via a transmission 3. The tube 4 emerging from the cold pilger mill moves with intermittent feed in the direction of the arrow 5 and is intermittently rotated in the direction of rotation 12.

The cutting device according to the invention consisting of a saw 9 and a clamping bush 10 is arranged on a carriage 6 which can be run by means of a member 8 on a path 7 at a distance a from the cold pilger mill roll stand 1. Has been done.

The clamping bush 10 can be rotationally driven at a constant speed by a method (not shown) to tighten the pipe 4 from the periphery. Due to the continuous rotation of the clamping bush 10, the tube 4 in this area is also continuously rotated.

Since the tube 4 is rotated intermittently in the cold pilger mill, it is temporarily elastically twisted in the section a. This twist does not damage the tube 4 and allows the saw 9 to be driven at the same cutting speed to be used for cutting the tube 4, thus cutting the same amount of material in the same unit time. to enable.

In order to allow a synchronous movement of the saw 9 and the tube 4 during the forward movement 5 of the tube 4, the carriage 6 forces the forward movement of the tube 4 together when the clamping bushing 10 is tightened. Clamping Bush 1 as you have to
The 0 and the saw 9 are fixed in a common carriage 6. Dolly 6
Rolls on the path 7 and allows the pipe 4 to be separated.

When the carriage 6 reaches its end position or when the pipe 4 is cut, the return cylinder 11 returns the carriage 6 to its initial position for cutting the next pipe length.

[Brief description of drawings]

FIG. 1 is a greatly simplified schematic of the device of the invention.

[Explanation of symbols]

 1 cold pilger mill 2 drive device 3 transmission device 4 pipe 5 arrow indicating the forward direction of pipe 6 bogie 7 moving path 8 rolling member 9 saw 10 clamping bush 12 pipe rotation direction a cold pilger mill roll stand and bogie Interval of

Front page continuation (72) Inventor Horst Steinerz, Germany 4156 Willich 3, Kunigsdorf 89, Germany 89 (72) Inventor Werner Henze Germany, Day 4018 Langenfeld, Helenenstraße 15

Claims (4)

[Claims] 1. Cold rolling during rolling in a cold pilger mill, which comprises a reciprocating roll stand, in which the tube undergoes intermittent feed and intermittent rotation in the region of one or two dead centers of the roll stand. In a method of cutting a Pilger-rolled tube to shorten it, in the region of the distance defined by the material and dimensions behind the rolling zone, the tube is temporarily elastically twisted to an average rotational speed of the tube. A method for cutting to shorten a cold pilger rolled tube, characterized in that a corresponding constant speed rotation is forced on the tube and the cutting of the tube takes place in this region. 2. A method for cutting a cold pilger rolled tube to shorten it according to claim 1, characterized in that the cutting of the tube is performed in synchronism with the longitudinal advance movement of the tube. 3. A cold pilger rolled tube is twisted at the cold pilger mill roll stand exit side,
3. A device for carrying out the method according to claim 1 or 2, wherein a cutting device having a cutting and cutting tool and a pipe clamping device and arranged so as to be movable along the pipe axis is used. A cutting bush is provided at a position spaced from the garmill roll stand exit side at a distance (a) that allows elastic twisting of the tube (4), and is clamped by a constant rotation to enclose and clamp the tube periphery. A device for cutting a cold pilger rolled tube to shorten it, wherein the cutting device has (10). 4. A cutting device is provided on a carriage (6) which is linearly drivable in synchronism with the longitudinal forward movement of the pipe (4) and is movable on a moving path (7). Apparatus for cutting cold pilger rolled pipes according to claim 3 for shortening.